Question

我正在从json数据中解析图像列表，我需要将图像添加到Picasso然后根据用户点击的位置显示它但我有一个错误：

FATAL EXCEPTION: main
    java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
      at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
      at java.util.ArrayList.get(ArrayList.java:308)
      at com.example.moayed.appshow.Adapters.ImageListAdapter.onBindViewHolder(ImageListAdapter.java:41)
      at com.example.moayed.appshow.Adapters.ImageListAdapter.onBindViewHolder(ImageListAdapter.java:18)

班级

public class ImageListFragment extends Fragment {

List<AppShowModule> appShowModules;
List<AppShowModule> imagesModule;
RecyclerView AppRecyclerView;
RecyclerView.Adapter imageRecyclerViewadapter;
List<String> imageUrls;
String feedKey = "feed";
String entryKey = "entry";
String imageKey = "im:image";
String labelKey = "label";
String jsonUrl = "https://itunes.apple.com/jo/rss/topfreeapplications/limit=50/json";
RequestQueue requestQueue;
private RecyclerView.LayoutManager mLayoutManager;
public ImageListFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_image_list, container, false);
}
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    AppRecyclerView = (RecyclerView) getView().findViewById(R.id.imageRecyclerView);
    imagesModule = new ArrayList<>();
    appShowModules = new ArrayList<>();
    imageUrls = new ArrayList<>();
    JsonAppShowData();
}
public void JsonAppShowData() {
    final JsonObjectRequest jsonObjectRequest = new JsonObjectRequest( jsonUrl, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {  try {
            JSONArray jsonArray = response.getJSONObject(feedKey).getJSONArray( entryKey );
            AppShowModule appShowModule = new AppShowModule();
            int x = appShowModule.getId();
            for (int i = 0 ; i<jsonArray.length() ;i++)
            {
                JSONArray imageArray = response.getJSONObject(feedKey).getJSONArray(entryKey).getJSONObject(x).getJSONArray(imageKey);
                for (int j = 0; j < imageArray.length(); j++) {
                    String image = imageArray.getJSONObject(x).getString(labelKey).toString();
                    imageUrls.add(image);
                    appShowModule.setAllimage(imageUrls);
                    appShowModules.add(appShowModule);
                }}
                imageRecyclerViewadapter = new ImageListAdapter(appShowModules, getContext(), imageUrls);
                AppRecyclerView.setAdapter(imageRecyclerViewadapter);
            } catch (JSONException e) {
                e.printStackTrace();
            }}
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e( "LOG", error.toString() );
        }
    } );
    requestQueue = Volley.newRequestQueue( getContext() );
    requestQueue.add(jsonObjectRequest);
    mLayoutManager = new GridLayoutManager( getContext().getApplicationContext(),3);
    AppRecyclerView.setLayoutManager(mLayoutManager);    }}

适配器

public class ImageListAdapter extends RecyclerView.Adapter<ImageListAdapter.ViewHolder> {
List<AppShowModule> appShowModules;
List<String> imageUrl;
AppShowModule appShowModule;


Context context;
public ImageListAdapter(List<AppShowModule> appShowModules, Context context ,List<String>imageUrls
){
    super();
    this.imageUrl =imageUrls;
    this.appShowModules = appShowModules;
    this.context = context;}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from( parent.getContext() ).inflate( R.layout.imagelayout, parent,false );
    ViewHolder viewHolder = new ViewHolder( v );


    return viewHolder;}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
AppShowModule appShowModule = new AppShowModule();
        Picasso.with(context).load(appShowModule.getAllimage().get(position)).into(holde  r.appImage);
}
public int getItemCount() {
    return imageUrl.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
    public ImageView appImage;
    public ViewHolder(View itemView) {
        super(itemView);
        appImage = (ImageView) itemView.findViewById( R.id.appImage);


    }}}

Answer 1

问题出在你的onBinderView方法中，你通过创建新实例来初始化AppShowModule，然后在尝试访问已经声明为new且已经为空的数据之后。

public void onBindViewHolder(ViewHolder holder, int position) {
AppShowModule appShowModule = new AppShowModule();
        Picasso.with(context).load(appShowModule.getAllimage().get(position)).into(holde  r.appImage);
}

更改上面的代码如下：

public void onBindViewHolder(ViewHolder holder, int position) {
AppShowModule appShowModule = appShowModules.get(position);
//Get the position from the list of your `appShowModules` and then try to access image from `AppShowModule`.
        Picasso.with(context).load(appShowModule.getAllimage().get(position)).into(holde  r.appImage);
}

希望这会对你有所帮助。

如果有任何疑问，请告诉我。

将图像列表传递给毕加索时出错

1 个答案: